GREAT DOG POEM NO. 2 Now that the great dog I worshIpped for years Has become none other than myself: I can look within And bark, and I can look at the mountains down the street And bark at them as well. I am an eye that sees itself Look back, a nose that tracks the scent of shadows As they fall, an ear that picks up sounds Before they are born. I am the last of the platinum Retrievers, the end of a gorgeous line. But there's no comfort being who I am. I roam around And ponder fate's abolishments until my eyes Are filled with tears and I say to myself: "0 h, Rex, Forget. Forget. The stars are out. The marble moon slides by." had very low sperm counts. The case of the tall man, whose sperm-producing cells seemed unaffected by the presence of estrogen in his body, illustrates that some- tiling other than estrogen can be respon- sible for low sperm counts. In this sce- nario, other chemicals in the environment may affect the hormonal balance by blocking either the estrogen receptors or the androgen receptors, or both. It is pos- sible that those chemicals are even more potent in their effect than environmental estrogens. Dioxin, which is a by-product of chemical manufacturing and of the pulp-and-paper industry, is present at low levels nearly everywhere in the environ- ment, and it can cause an astonishing amount of damage. "Our studies [in rats] show that a single dose of dioxin admin- istered during pregnancy permanently re- duces sperm counts in the males by about sixty per cent," Earl Gray, who is a re- search biologist at the Environmental Protection Agency, told a House ofRep- resentatives subcommittee in 1993. Gray's lab has also been examining a widely used pesticide called vinclozolin. It is an anti- androgen, which is to say that it blocks the receptors of the male hormone. Vin- clozolin administered to a pregnant rat emasculates the male pups to the point that they are indistinguishable from the females But it has little effect on the fe- males. It is clear that there are a number of other chemicals- that have the ability to -MARK STRAND imitate or block human hormones, and scientists like Gray are only beginning to take an inventory of such compounds. 'With sperm counts, I've been more im- pressed by the dioxins and PCBs than by the estrogens and anti -androgens," Gray saId. 'We get surprising effects at rela- tively low doses." Even Richard Sharpe, whose research did so much to advance the environmental- estrogen hypothesis, admits that it re- mains unproved. "The remarkable thing about the whole DES episode in human beings is that, for something that was conducted on such a large scale, using co- lossal amounts of such a potent hor- mone, the effects on both the male and the female offspring were of such low incidence," Sharpe says. For Sharpe and many other scientists, the hunt for the cause of declining sperm counts is far from over. Lately, he has actually begun to wonder if humanity has undergone an evolutionary mutation that may have se- riously jeopardized its ability to produce sperm. W HATEVER combination of factors is causing the sperm counts to fall, the answer seems to lie in the differences between the Danes and the Finns. A 1993 survey of six studies of Finnish men found that their average sperm count was a hundred and fourteen million per milli- litre-nearly double the worldwide aver- 53 age and two and a ha1f times that of Den- mark. (Sweden and Norway have sperm counts slightly above Denmark's) As Skakkebæk would have predicted, on the basis of the high Finnish sperm counts, the rate of testicular cancer in Finland is a fourth that of Denmark, and the preva- lence of malformed penises is approxi- mately a third. Yet these countries are near neighbors, with much in common in their diets, their cultures, and their envi- ronments. How could the men in these countries vary so widely in their sperm counts? Several prominent scientists are inves- tigating what is informally called the Mystery of the Finnish Testicles. Some of the explanations seem counterintuitive, if not comical. For instance, there is the well-known Finnish fondness for saunas. A hot sauna should temporarily flatten a man's sperm count. Spermatogenesis is extremely sensitive to heat-that's why a man's gonads are outside his body, and why the scrotum expands and contracts. Sperm like to be about two degrees cooler than the temperature of the body. But few scientists accept the notion that saunas somehow acclimate the testicles to higher temperatures than those which are thought to be caused by central heating and the modern sedentary life style. Jyrki Suominen, who is an androlo- gist at the University of Turku, in Fin- land, and his colleague Matti Vierula, who is a lecturer at the university's In- stitute of Biomedicine, have a theory that could provide a novel solution to the Finnish-testicle mystery. "Studies show that man is a seasonal breeder," Vierula told me in Suominen's office, and he pointed to a graph that correlated the variations in the average Finnish sperm count with the months of the year. "Sperm counts are highest in the winter." Perhaps the summer heat depletes the sperm and Finland is less likely to suffer such losses because it has a cooler cli- mate. Some researchers have theorized more broadly that global warming has thrown a blanket over sperm production. A study in New Orleans, however, com- pared sperm concentrations of men who worked in air-conditioned buildings with those of men who worked outdoors, and, surprisingly, both groups showed a twenty-per-cent decline in their sperm count during the summer months. This suggested that temperature was not a factor, though some other seasonal dif-